HS2 is already gobbling up land and starting enabling worksin Birmingham. I attended a public communications event about Curzon Street station (the HS2 terminus in Birmingham) the other week organised by the Community Engagement Team of Laing O'Rourke and Murphy and had a long discussion with them about engaging the OpenStreetMap community. The upshot was that they would investigate how to work with us, particularly as I could demonstrate the following day after they took possession of another lalrge car park that our map was updated within an hour.
They also gave me information about the HS2 Community and Environment Fund which might be worth investigating. There will be massive amounts of mapping work for us to do and ny fear is that it will probably overwhelm us as a community of volunteers as presently organised and this funding route might help us.
I see this as a great opportunity to demonstrate the power of OSM and also a great project for the UK Chapter to organise.